Method of preserving fruits and vegetables



2 ,8 l 9 72 Patented Jan: 1743,1958? METHOD OF PRESERVING FRUITS AND VEGETABLES" Albert A; Robbins, West "Covina, Calif;; assignor of. one tenth toPhilip Subkow; Los'Angeles; Calif? No'Drawingt- Application April:3,,1952n Serial.-No.-- 280,373:

zwelaime (Cl 99 -154 This application is a continuation-in-part of application: SerialNo. 195,149; filedNovembier 10,- 1950, and; relates tothe preservation'of -thequality of fresh fruits; flowers; andtvegetables, all inclusivelyhereinafterreferred totasagricultural products, by the-treatment thereof. with solar-- tionsrofacinnamate ion, both in: ItS:aCid;fll1d Sallf0I-IDS; dissolved in water.

Lhave .foundthatthe storagelifel-of': such treated agricultural products; and particularly white:Irishvpotatoes,- sweet potatoes; and onions, is-increased materially,='by=my/ treatment. The: process consists; in. wetting; the agriculw tur-al product =with a' water'solutioniofrthewinnamieaeid. or cinnamic acid salt in the-presencezof dissolvedalpha or" betanaphthol. The cinnamate. ion, particularly in.the presence OffilPhfi-Ofibtfi naphthol, appears to: havea'preservative action: on the agricultural product; in thatuthe; properties of the :freshly' picked agricultural. productxare; preserved for a longer period 'if.so:treated; tharrxthoserofi. untreated agricultural products.

Lmay employeither'the cinnamic acids orzsalts of chinamic "acid; employing: Preferably the: salts rwhose: metal; ions-rare physiologically; harmless,-,such1as:the; sodium salt; which ISIHOTS' soluble. than: the acid-form; Thistiacidahasia low=:solubility;in-. water, yet I havei'ciundxthatsasolution: of commercial transcinnamic acid in: water'atatmospherio temperature is-highly1 eflicient for. my purpose; I. may also employwater:solutionszof the cisform: f 'thewCl'I1- namate ion in the form of acid or'saltskinthe :presenceofi; saturated sol ofbetanapht-hol-or alphapaphtolz- Thet-processis applicable to fruits and vegetables for example, apples, pears, grapefruit, lemons-oranges; apri-- cots avocados,.legumes, such as string -beans;.Lirna beans, kidneygbeans berries, such as strawberries, raspberries,-: blackberries, loganberries, youngb'erries, etc., aszwellxas: to cucumbers; cherries, cranberries, dates, eggplant,.figs, guavasxmelons; such: asrmuskmelons, cantaloupes,rPersian"r. melons, honeydew, etc., nectarines, plums; prunes,;' peaches, pumpkins, peppers, both green-t ands-red; .pomegranates; persimmons, bananas, andcradishes;

In the case of the legumes, such as peas, Lima beanssand; kidneya beansgwith pods, limay shell thenrandr'wet the beans orxpeas, or:I may cut the stem from theapodandt treat the pod, particularly the cut end thereof.

In the caseof vegetables having ,acorky stem. or one havingggr'eaterpermeability to fluid, I mayleaveatgreaterfi amount of stem; for example, the banana, where thestem. ispithyorcorkyanda good conductor forfiuid, I may permit a .greater amount .ofistem toremaint However, in; this case, also, it is desirable to cut the vegetable from the. stern,- atthebutt; that is ..close to -the..leaf.y part. Thus, in the ,casesof lettuce,,corn, artichokes, .caulifiower, .celery, chard, kale, kohlrabi, pineapple, squash, etc., the vegetable. is cut closetoiheibutt thereof to remove. theistemortroot,

In the case of asparagus and broccoli,- where the stem is the edible portion of the vegetable, the stem may be 2 treated: by cuttiitgit asis: usualin present commercial; operations-and then treat-the vegetable"and'partieularlyi the cut portion of the stem.

In: the case of the root --type=.vegetables; such as potatoes and yams, I treat-the:p0tato and' yam a's'a unit,and-"in"tlie case of carrots, turnips; radishes and beets,- I may' also remove thegreens' so as to leave'the naked rooFor-treah the root 'and leaves: p

In the case of the leafy vegetables, such asmint; mus tard greens, parsley, spinach, and'watercress, I 'coatth'e entirerleaf; including the cut stem, as' w-ill bedescribed belbwi- Where;-as in thecase of 'grapesg the fr'uit-is sold inib'unches, I treal: them insuch bunches:

As indicated; instead of using'cinnam'ie acidPmay empfloy aiisolution otia 'saltof "cinnamicacid using awone cent-ration: asxlew as one part per million andup to five parts of cinnamate ion per10Oparts" of water orhi'g 1"" concentrations I prefer to employ-"the physiologically:/ harmlesszsalts of'these; acids' which have'a solubility a's high'lor higher than the acid; sinee-ifthey b'e lower-'l mays use' theJ'a'cidFitSelfL' I may usethe cinnamate saltbftlie Na; K, NH'por of thealkaline earth metal, such as Ca 01" Mg andiheavy'metal Cu, Ag, or other'oligodynamicmetal' ionss Forl'commercial operations I" propose to introducethe cinnamieiacid'and the naphth'ol into the wash water; The-:1 wash! watermay be passedth'rough a bed' of the' cinnamie acid and alpha or beta naphthol containediirany suitable" container or I' may introduce the 'cinnam'ic acidinto the container in which the potatoes are-washed -in"'.anysuit able" manner: The transcinnamic facidihas a? solubility ofi about .1 part? per parts I of distilled? water=xat 25 and':.04 part at 18 C. Beta naphth'olris soluble 'ing coldtl waterrat the rateof .1 part in 100 parts ofi water: 'lhexso'li-tubili'ty of the cinnamic acidfin ordinary waterzwills'rlependga somewhatzontzthe pH 'ofithe water; inz-softwatersisalkalinee with Na, arhigher'concentration ofzthe:cinnamatezrions" may be obtained due" to. the highersolubilitrofi ther dea veloped. cinnamate salt; In:acidZwaterszazlowerzsolubilityu results. In; neutral tori alkaline water; the cinnamic-::aeidd will lower the pH of the water and placei'it:omlthemcidlt sides The use of acid waters in such-circumstances:has, as I have found, a: beneficial eilect in: prolongi'ngttheestons age life of vegetables, and. particularly potatoesabotha Irish and isweet, and i onions.- They; may be: storedsfori prolonged periods without refrigeration.

I may employ waters having a relatively lowltempemture; down as-low as-O." G. and-.the'saturated solutiom the cinnamic acid. at .such temperature:appearsrsufiicienti to produce. theabove results: Irmayal'so employywaters-s as high as boiling water for this purpose andglobtaimae higher concentration of cinnamic acid. The time;:of;-con.- tact ofthe solution of the'acid with the fruitzonvegetable for treatment may beadju'sted; usingaa'longer time for the lower concentrations; I have foundfithatwno alterationaim the washing techniques commercially employed is :required-i irrespective of the-temperatureofihe water I have washed new whitehpotatoes,iasttheywcomerfrorw the field with solutions:of-tcommerciallltnanscinnamiceacid, and saturated with. naphthol in whichv the acidu-isrusedl im concentrations. as.-low as-one part :per million/of: water and 11191110 saturated isolutions at-atmospheric: temperature-r: and. have compared" their. storage and.presenvativetqualiaties with potatoes Washedtwithtwaterv alone Thet new, potatoes treated. with. the .cinnamic-V acid-.1 and, naphtha-l solution have a brighter. skin comparedawithihe darker," skin. ofnewt potatoeswwashedt with .water alone. Ilhave; kept the potatoes-.twashed. with. the. cirinamidacidfandf, naphthol solution fora period'fof many weeks at 'ordiiiary summer temperature without refrigeration and the potatoes have remained fresh, firm, and without blemish. I have not yetdelermined the full length of the storage period. Sprouting takes longer than with untreated potatoes. Such potatoes as are injured in handling and wash mg appear to heal, in that the scars callous over without developing rot or decaying spots. This is also true of injured potatoes which have started to rot at the wound. Potatoes washed with waterunder parallel conditions 'go bad in a very few days of storage.

Thecinnamate ion and naphthol treatment also reduces the loss of weight of potatoes and yams which always results from storage of potatoes. This loss of weight apparently results from dehydration of the potatoes. It has been observed that if this loss of weight, becomes large, discoloration and even rotting of the potatoes occurs. While I do not know whether these phenomena are related as to cause and effect or result from the same or different but simultaneous processes occurring in the potato during storage, and I do not desire to be bound by any theory of this action. I have observed as a fact that potatoes, and particularly new white potatoes (sometimes referred to as Irish potatoes) when treated by my process lose considerably less weight in storage and remain unspoiled and fresh appearing for longer periods than do such potatoes untreated. Sprouting also is delayed. In the case of sweet potatoes and yams, the yellow color becomes intensified. Melons treated by this procedure may be held without further ripening for from ten to fifteen days under normal commercial refrigeration.

Onions were washed with the cinnamic acid and naphthol solution and remained fresh, with no darkening or spoilage after two months storage at ordinary room temperature, while a check of untreated onions were bad and darkened in two weeks.

I have found it advantageous to contain the crystals of transcinnamic acid and naphthol in a porous fabric bag and enclose the bag in a container formed of a copper mesh and insert the bag into a closed iron or steel chamber through which I may circulate water, which thus passes into the chamber through the copper mesh and the fabric bag, dissolving the crystals. I am also of the opinion that some copper cinnamate and iron cinnamate are formed by corrosion and that these salts, and particularly the copper ion, are also helpful. The solution then made may be passed, with or without further dilution into and through vats in which the agricultural products may be placed or dipped.

While I may thus add oligodynamic ions to the cinnamate solutions, I find that the activity of the cinnamate ion and the naphthol is sufficient and the examples given above were made by dissolving the cinnamic acid as such in water.

While I have described a particular embodiment of my invention for the purpose of illustration, it should be understood that various modifications thereof may be made within the spirit of the invention as set forth in the appended claims.

I claim:

1. A process for treating agricultural products chosen from the group consisting of fruits and vegetables, comprising wetting the agricultural products with a water solution of cinnamate ions and naphthol.

2. A process for treating agricultural products chosen from the group consisting of fruits and vegetables, comprising wetting the agricultural products with a water solution of trans-cinnamate ions and naphthol.

3. A process for treating agricultural products chosen from the group consisting of fruits and vegetables, which comprises wetting the agricultural products with a water solution of cinnamic acid and naphthol.

4. A process for treating agricultural products chosen from the group consisting of fruits and vegetables, which comprises wetting the agricultural products with a water solution of trans-cinnamic acid and naphthol.

5. A process for treating agricultural products chosen from the group consisting of fruits and vegetables, comprising wetting the agricultural products with a water solution of cinnamate ions in concentration ranging from one part per million up to saturated solution and naphthol.

6. A process for treating agricultural products chosen from the group consisting of fruits and vegetables, comprising wetting the agricultural products with a water solution of trans-cinnamate ions in concentration ranging from one part per million up'to saturated solution and naphthol. i

7. A process for treating agricultural products chosen from the group consisting of fruits and vegetables, which comprises wetting the agricultural products with a water solution of cinnamic acid in concentration ranging from one part per million up to saturated solution and naphthol.

8. A process for treating agricultural products chosen from the group consisting of fruits and vegetables, which comprises wetting the agricultural products with a water solution of trans-cinnamic acid in concentration ranging from one part per million up to saturated solution and naphthol.

9. A process for treating agricultural products chosen from the group consisting of fruits and vegetables, comprising wetting the agricultural products with a Water solution of cinnamate ions in concentration ranging from one part per million up to saturated solution, oligodynamic metal ions and naphthol.

-10. A process for treating agricultural products chosen from the group consisting of fruits and vegetables, comprising wetting the agricultural products with a water so lution of trans-cinnamate ions in concentration ranging from one part per million up to saturated solution, oligodynamic metal ions and naphthol.

11. A process for treating agricultural products chosen from the group consisting of fruits and vegetables. which comprises wetting the agricultural products with a water solution of cinnamic acid in concentration ranging from one part per million up to saturated solution, oligodynamic metal ions and naphthol.

12. A process for treating agricultural products chosen from the group consisting of fruits and vegetables, which comprises wetting the agricultural products with a water solution of trans-cinnamate ions in concentration ranging from one part per million up to saturated solution, oligodynamic metal ions and naphthol.

13. A process for treating Irish potatoes, comprising wetting the Irish potatoes with a water solution of cinnamate ions and naphthol.

14. A process for treating Irish potatoes, comprising wetting the Irish potatoes with a water solution of transcinnamate ions and naphthol.

.15. A process for treating Irish potatoes which comprises wetting the Irish potatoes with a water solution of cinnamic acid and naphthol.

.16. A process for treating Irish potatoes, which comprises wetting the Irish potatoes with a water solution of trans-cinnamic acid and naphthol.

17. A process for treating yams, comprising wetting the yams with a water solution of cinnamate ions and naphthol.

18. A process for treating yams, comprising wetting the yams with a water solution of trans-cinnamate ions and naphthol.

'19. A process for treating yams, which comprises wetting the yams with a water solution of cinnamic acid and naphthol.

20. A process for treating yams, which comprises wetting the yams with a water solution of trans-cinnamic acid and naphthol.

21. A process for treating onions, comprising wetting the onions with a water solution of cinnamate ions and naphthol.

22. A process for treating onions, comprising wetting the onions with a water solution of trans-cinnamate ions References Cited in the file of this patent g g f ti h t UNITED STATES PATENTS process or trea ng ODlOIlS, w 1c comprises we ting the onions with a water solution of cinnamic acid and 1627342 Sabahtschka May 1927 naphthol 5 1,961,740 Conquest Juno 1934 24. A process for treating onions, which comprises wet- OTHER REFERENCES ting the onions with a water solution of transcinnamic acid Naturg January 29, 1944, page 141, article entitled and naphthol. Aerial Disinfection. 

1. A PROCESS FOR TREATING AGRICULTURAL PRODUCTS CHOSEN FROM THE GROUP CONSISTING OF FRUITS AND VEGETABLES, COMPRISING WETTING THE AGRICULTRAL PRODUCTS WITH A WATER SOLUTION OF CINNAMATE IONS AND NAPHTHOL. 